Photographic enlarger



March 2, 1943. 'A LEONARD 2,312,561

PHOTOGRAPHIC ENLARGER.

Filed Feb. 12, 1941 2 Sheets-Sheet l 2 INVENTOR ANTHON A. LEONARD ATTORNEY5 March 2, 1943. A. A. LEONARD PHOTOGRAPHIC ENLARGER Filed Feb. 12,1941 2 Sheets-Sheet 2 INVENTOR ANTHON A. LEONARD Patented Mar. 2, 19432,312,561 rno'rooasrmo ENLARGER Anthon A. Leonard, Glenside, Pa.,assignor to De Jnr-Amsco Corporation, Shelton, Conn, a cor poration ofNew York Application February 12, 1941, Serial No. 378,494

9 Claims.

house for axial flow of air for cooling purposes,

and to provide inlet passages so located that the upward flow of aircaused by the heated lamp house will also cool the condenser lenses. Afurther object is to provide an extra cooled jacket around the lamphouse, so as to avoid danger of injury on contact with the same. Anotherobject is to cool both the inner case and the exterior jacket, by meansof appropriately divided air streams.

A further object is to provide a top assembly for the lamp house whichwill afford free discharge of air from both the jacket space and theinterior of the lamp house, the air being discharged over a large area,while preventing passage of light out of the lamp house, and thesettling of dust into the lamp house. Another object is to provide thetop assembly with a maximum area for radiation of heat.

To the accomplishment of the foregoing, and such other objects as willhereinafter appear, my invention consists in the lamp house andcondenser elements and their relation one to the other as hereinafterare more particularly described in the specification and sought to bedefined in the claims. The specification is accompanied by drawings. inwhich:-

Fig. l is a perspective view of an enlarger embodying features of myinvention;

, Fig. 2 is a partially sectioned elevation of the lamp house;

Fig. 3 is a partially sectioned plan view taken in the plane of the line3-3 of Fig. 2;

Fig. 4 is a horizontal section taken in the plane of the line 4-4 ofFig. 2;

Fig. 5 is a transverse section showing a detail, and taken in the planeof the line 5-5 of Fig. 4;

Fig. 6 is a schematic sectional view through the lamp house explanatoryof the flow of air through the same for cooling purposes; and

Fig 7 is a similar view explanatory of the manner in which light fromthe lamp house is baffled.

Referring to the drawings, and more particularly to Fig. 1, the enlargercomprises a base 52, an upright column 14 rigidly mounted on base i 2, ahead generally designated i 6, and carried on a bracket i8 which isslidable on column M. The

head [6 comprises a lamp house 20 with a bellows 22 therebeneath. Thenegative may be placed in a negative stage 24, while a lens is mountedat 26. The lamp is energized through an electric supply cord 28, whichpasses downwardly through hollow column i4, and thence outwardly at 38for connection to a household wiring outlet.

Referring now to Fig. 2, the lamp house con1- prises a cylindrical innercase 32 beneath which is carried a condenser housing or barrel 3 comtaining the usual piano-convex condenser lenses 36. A lamp 38 is carriedin a socket 4B surrounded by a frustro-conical light shield d2. A heatabsorbiiig glass lid is disposed in the top of the lens housing, betweenthe lam and the lenses 36.

The inner case 32 is imperiorate and is surrounded by an irnperiorateouter jacket 45 spaced therefrom. A highly perforate ventilator band 48is disposed around and spaced from the lens housing 34. A multipleflanged cap assembly, generally designated as, is disposed at the top ofthe lamp house and is so arranged as to permit upward discharge oi airand radiation of heat while bafliing the escape of light and settling ofdust.

The cooling action of the lamp houw is more clearly shown in Fig. 6,referring to which it will be seen that heating and consequent upwardnew of air in the lamp house causes intake of at 52 through theapertures in ventilator band it. The cool air flows upwardly along thelens hous= ing 34 and cools the same. The rising then divides, one artflowing inside the case 32, as is indicated by the arrows 5 3. This partis guided upwardly by an annular wall 56. The heated air then flowsupwardly around the light baffle i2 and is discharged between upwardlyflanged caps 58' and 60, as is indicated by arrow also between cap 60and center cap ii, as is indicated by arrow 66.

Another component of the air entering the van" tilator band fiOWSupwardly through the jacket space between case and jacket air cools theinner case 32, and prevents heating of the outer jacket 58, so that thelatter remains comparatively cool at all times. The air flowing upwardlythrough the jacket space is discharged between an outer flange 88 and acap it, as is indicated by arrow i2, while another part is dischargedbetween cap "iii and cap 53, as is indicated by arrow i i.

The action of the lamp house in preventing the escape of unwanted lightwill beclear from iiispection of Fig. l, in which it will be seen. thatlight ray I6 clearing baflle d2 is reflected back at I8. Light ray 80clearing baiiie 50 encounters wall 32, and even if repeatedly reflectedfinally is stopped by perpendicular reflection at 82.

Even if it be assumed that every point on the true interior of the lamphouse is a source of light, it will be found that any light rays passingoutside the shield 42, such as the ray 8 3, will be trapped as indicatedby the reflections 85, 80, and 90. Similarly, a light ray clearing thebaiile 5%, such as the ray 92, will be bailied by reflections indicatedat 90, 96, and 98.

Various other rays maybe drawn, but it will be found that the lamp houseas here designed is light-tight, and this is an important advantage notonly for general work, but also for threecolor work.

The constructional details of the lamp house may be described withreference to Figs. 3 through 5 of the drawings. The lamp house comprisesa cylindrical sheet metal inner case 32 and an outer jacket 46 carriedbetween an upper preferably die-cast member I and a lower preferablydie-case member I02. The inner case 32 is secured to members I00 andI02, while the outer jacket 35 is merely carried therebetween.Specifically, inner case 32 has a number of studs I04 secured thereto byscrews I06, and these studs pass upwardly through member I00. They alsofunction to hold the upwardly flanged cap III in position, as by meansof nuts I08 and I I0. The inner case 32 is secured to the lower memberI02, as by means of screws I I2 (Figs. 4 and 5). These screws pass intothickened fins I M which replace some of a series of thinner radial finslid, these fins all being die-cast integrally with lower member I02. Inthe present case there are eight flns, two of which are thickened. Thefins project radially outward from the guide and bafile wall 56, andbear against the inside of case 32.

The bottom member I02 further includes an upwardly and downwardlyextending light bame I I8 connected by a web I20 to upwardly extendingflange I22 and downwardly extending flange I24. The outer jacket 46 isreceived within upwardly extending flange I22. The downwardly extendingflange I24 is'connected by means of screws I26 to the upper edge of theventilator band 08. The lower edge of this band is connected by means ofthumb screws I30 to a die-cast generally square member I32 having an armISI which leads to the bracket I8 mentioned in connection with Fig. l.Member I32 is secured to another generally square member I36 by means ofthumb screws I38, and the upper end of the bellows is connected at thispoint. The member I36 also serves to hold the condenser housing 3 3 inposition, this resting against a ledge I40 on member I36.

It will be understood that the web I20 of member I02 is cut away to formlarge area ventilating passages, these being indicated at I62 in Fig. 4.Similarly, the web It in upper member I00 is cut away to form ampleventilating passages of similar character.

The upwardly flanged cap 58 rests on a raised annular surface I48forming a part of the upper die-cast member I00. Caps 60 and 00 aredisposed thereabove and are all secured in position by screws I50, thesescrews passing through suitable tubular spacers I52 and IS I. The lowerends of the screws are received in threaded, holes in the raised surfaceI48, two of these being indicated at ISI in Fig. 3.

This raised surface is cut away to form large aaiacei ventilatoropenings indicated at I56 in Fig. 3. The lamp socket d0 (Fig. 2) issecured at the center of this surface, together with the upper edge oflight bafiie 82. The conductors from the lamp socket extend to aconnector I60 (Fig. 4) which is mounted on cap 5d. A part of the flangeof the next lower disc 60 is cut away at I02 to clear a passage for themale connector member I84 (Figs. 2 and 3) at the end of the electricsupply cord 23.

It is believed that the construction, method of assembly, and operationof my improved lamp house, as well as the many advantages thereof, willbe apparent from the foregoing detailed description. It will also beapparent that while I have shown and described my invention in apreferred form, many changes and modifications may be made in thestructure disclosed without departing from the spirit of the inventionas sought to be deflned in the following claims.

I claim:

1. A top assembly for a vertically disposed cylindrical lamp house, saidassembly comprising a series of circular upwardly flanged caps ofprogressively smaller diameter superposed in the order of decreasingdiameter, said caps being annular and spaced at their inner and outerperipheries, each cap having a flat annular portion surrounded by anupwardly turned cylindrical portion, a topmost circular imperforate caphaving a downwardly turned flange, and means including spacers to holdsaid caps in desired spaced superposed relation, the assembly affordingready egress of air, but bafiling the passage of light.

2. A top assembly for a vertically disposed cylindrical lamp house, saidassembly comprising a lamp socket, a frustro-conical light shielc'.atsaid socket, and a series of circular upwardly flanged caps ofprogressively smaller diameter superposed in the order of decreasingdiameter, said caps being annular and spaced at their inner and outerperipheries, each cap having a flat annular portion surrounded by anupwardly turned cylindrical portion, a topmost circular imperforate caphaving a downwardly turned flange, and means including spacers to holdsaid caps in desired spaced superposed relation, the assembly aflordingready egress of air, but baflling the passage of light, the resultingdischarge passagesbetween the upwardly turned flanges of the capsoccupying a large portion of the area of the top of the lamp house, andthe multiple flanges providing a substantial surface area for heatradiation.

3. A lamp house for an enlarger, said house comprising a cylindricalinner case, a cylindrical outer jacket surrounding but spaced from saidcase, a condenser housing beneath said case, a perforate ventilator bandsurrounding but spaced from said condenser housing, passages between theVentilator band, the case, and the jacket space, for dividing airflowing upwardly \from the ventilator band past the condenser housingand for permitting part of said air to be drawn into the lamp case forupward flow through the case, and for permitting the remainder of saidair to be drawn upwardly through the jacket space between the case andjacket, and multiple flanged caps supported in spaced telescopingrelationto each other at the top of said lamp house for affording freeupward discharge of air from both the case and, jacket while preventingpassage of light.

4. A lamp house comprising a cylindrical case, a condenser housingbeneath said case. a ventilator band surrounding but spaced from saidcondenser housing, and a cast metal member for holding said parts inassembled relation, said member having a guide wall spaced inwardly ofsaid case, fins extending radially from said guide wall to said case,and an external flange extending downwardly for receiving saidventilator band.

5. A lamp house comprising a cylindrical case, a condenser housingbeneath said case, a ventilator band surrounding but spaced from saidcondenser housing, and a cast metal member for holding said parts inassembled relation, said member having a guide wall spaced inwardly ofsaid case, fins extending radially from said guide wall to said case, alight baflie between said case and lens housing, and an external flangeextending downwardly for receiving said ventilator band.

6. A lamp house comprising a cylindrical case, a cylindrical jacketsurrounding but spaced from said case, a condenser housing beneath saidcase, and a cast metal member for holding said parts in assembledrelation, said member having a guide wall spaced inwardly of said case,fins extending radially from said guide wall to said case, and anexternal flange extending upwardly for receiving said jacket.

'7. A lamp house comprising a cylindrical case, a cylindrical jacketsurrounding but spaced from said case, a condenser housing beneath saidcase,

and a cast metal member for holding said parts in assembled relation,said member having a guide wall spaced inwardly of said case, finsextending radially from said guide wall to said case, a light baiilebetween said case and lens housing, and an external flange extendingupwardly for receiving said jacket.

8. A lamp house comprising a cylindrical case, a cylindrical jacketsurrounding but spaced from said case, a condenser housing beneath saidcase, a ventilator band surrounding but spaced from said condenserhousing, and a cast metal member for holding said parts in assembledrelation, said member having means to hold said case, a light bailiebetween saidcase and lens housing, and external flanges extendingupwardly for receiving said jacket and downwardly for receiving saidventilator band.

9. A lamp house comprising a cylindrical case, a cylindrical jacketsurrounding but spaced from said case, a condenser housing beneath saidcase, a ventilator band surrounding but spaced from said condenserhousing, and a cast metal member for holding said parts in assembledrelation, said member having a guide wall spaced inwardly of said case,fins extending radially from said guide wall to said case, and externalflanges extending upwardly for receiving said jacket and downwardly forreceiving said ventilator band.

ANTHON A. LEONARD.

